Washington Hospital's Outpatient Imaging Center recently upgraded its magnetic resonance imaging (MRI) scanner to provide the latest advances in this important tool for diagnosing and treating various medical conditions, including cancer.

"We are pleased to be able to offer this advanced MRI technology, which is not commonly available outside of large university hospitals," says radiologist Jacob Wouden, M.D. "The new MRI capabilities will enhance our already excellent Cancer Care Program even more, enabling local patients to have the highest quality imaging technology without having to travel across the Bay." Dr. Wouden is an MRI specialist who completed a magnetic resonance imaging fellowship at Harvard.

MRI is a non-invasive imaging procedure that uses a strong magnetic field and radio waves to produce detailed images of the inside of the human body. The magnetic field is produced by passing an electric current through wire coils in the MRI unit. Other coils, placed around the part of the body being scanned, send and receive radio waves to produce signals that are processed by a computer to produce a series of images.

"Surface coils are usually not sufficient to produce detailed images of areas such as the prostate gland and rectum," notes Dr. Wouden. "One of the capabilities our new system offers is endorectal MRI, in which a small coil is placed inside the rectum, giving us much greater visualization of prostate and rectal cancers."

Endorectal MRI is used after a biopsy and diagnosis of prostate or rectal cancer to help evaluate the extent of the cancer and define the proper course of treatment, according to Dr. Wouden.

"Endorectal MRI can determine the stage of prostate or rectal cancer, specifically whether it is still confined or has spread to surrounding structures such as the bladder, urinary tract, seminal vesicles, or nearby lymph nodes," he explains. "Choosing the proper treatment can be a complicated decision, and information from endorectal MRI can help guide the process. For example, if the cancer has spread outside the prostate gland, it might be more appropriate to do radiation therapy or chemotherapy, rather than surgery.

"We also inject a contrast agent so that the structure and surrounding blood vessels that we are examining show up more clearly," he adds. "A computer-aided detection software package helps assess how much and how quickly the contrast agent washes in and out. Because tumors have more blood vessels than surrounding tissues, the contrast agent moves in and out of tumors more quickly."

Dr. Wouden outlines some of the ways that endorectal MRI can also be used in pre-treatment planning for prostate cancer: "The MRI can show if the tumor involves the nerves surrounding the prostate, which might cause urinary incontinence or erectile dysfunction if damaged. That would help the surgeon plan a surgery to spare those nerves if the cancer has not spread there. For radiotherapy, the radiation oncologist needs to know where to apply the radiation, and the MRI can help pinpoint the location."

While primarily used to help stage cancers and determine treatment options, endorectal MRI may be used as an additional screening tool for prostate cancer in some cases. "Endorectal MRI can be useful if the doctor suspects prostate cancer because the patient's PSA level is high, but a biopsy of the prostate is negative and may have missed the cancer," Dr. Wouden says. "The MRI can direct a second biopsy to the correct location. In addition, if a patient has already had prostatectomy surgery but his PSA level rises again, an endorectal MRI could detect a local recurrence around the surgical site."

Dr. Wouden adds that endorectal MRI is just one of several new advanced MRI capabilities available at Washington Hospital. Others include:* MR enterography: Evaluation of the small bowel, especially for patients with known or suspected inflammatory bowel disease.* MR urography: Imaging of the urinary tract.* Hepatic MRI with Eovist: Evaluation of the liver and biliary system.* Adrenal MRI: Imaging of the adrenal glands (above the kidneys).* Advanced MR angiography including TRICKS: Evaluation of arterial disease throughout the body, including peripheral vascular disease in the limbs, the renal arteries (supplying the kidneys), carotid arteries (supplying the brain), mesenteric arteries (supplying the bowel), and the aorta (main artery supplying the body).